JPEG 2000 is a state-of-the-art continuous-tone image coding system. Based on wavelet transform technology followed by bit-plane coding, JPEG 2000 generally provides better rate-distortion performance than the discrete cosine transform based JPEG coding system. However, the real advantages of JPEG 2000 are features such as the access of different resolutions, progressive bit-rates from very lossy to lossless, access to regions-of-interest, and access to color components.
The JPM standard is described in “Information technology—JPEG 2000 Image Coding System—Part 6: Compound image file format, ISO/IEC 15444-6:2002” available from the ISO. JPEG 2000 Part 6 (JPM) is a file format designed to represent the visual appearance of a document. JPM provides an efficient way to store mixed raster content (MRC) data. JPM can provide excellent compression by use of the appropriate compressor. JPM allows multiple pages to be stored in a file. JPM also allows references to external files. The file can be large because there may be hundreds of pages or very high-resolution images. Thus, effective use of the JPM format requires the ability to extract parts of the file and re-assemble it under specific constraints. For example, it may be useful to extract a screen resolution version of the first few pages of a 500-page document or to extract the parts of the file according to a client's interest. With the advances in computer networking and personal computing devices, network access to document databases is increasingly important.
JPEG 2000 Part 9 (JPIP) is a standard for interactive communication of JPEG 2000 images. It is defined in the ISO Standard, “Information technology—JPEG 2000 Image Coding System—Part 9: Interactivity tools, APIs and protocols, ISO/IEC 15444-9:2004.” JPIP allows the region and resolution required by the client to be transmitted over a network. Additional requests for data are efficient in the sense that previously transmitted data is not repeated. JPIP is being extended to operate with JPM files (in addition to JP2 and MJ2 file formats previously supported), by the JPEG committee. This extension will become an amendment to the JPIP standard, “Information technology—JPEG 2000 Image Coding System—Part 9: Interactivity tools, APIs and protocols, AMENDMENT 1: API's, metadata, and editing,” it is currently in progress.
TRUEW (interactive access to JPEG 2000 imagery) includes image processing techniques that operate on JPEG 2000 and other compressed files. In TRUEW, the image objects are typically tiles in the original image and are stored as tile-parts in the compressed file. Tile-parts are selected from a JPEG 2000 compressed file based on spatial intersection with a view-window requested by a client. Upon selection, the objects are delivered in a special compressed format without transcoding, until all objects needed to fill the user's request have been delivered or a new view window request has been received from the client. For more information on TRUEW, see U.S. patent application Ser. No. 10/273,734, entitled, “Transport of Reversible and Unreversible Embedded Wavelets” filed Oct. 18, 2002; U.S. patent application Ser. No. 10/384,277, entitled, “Communication of Compressed Digital Images,” filed Mar. 7, 2003; and U.S. patent application Ser. No. 10/614,877, entitled, “Network Access to Partial Document Images,” filed Jul. 7, 2003, all assigned to the corporate assignee of the present application.
SmartNails are small representations of images or documents, like thumbnails or icons, but with more relevant information. The SmartNails methods include extracting data from the headers of a JPEG 2000 codestream. This allows regions of a JPEG 2000 image to be selected without doing pixel level processing which can be much more computationally complex and thus operate slowly. The SmartNails methods operate on a small part of a JPEG 2000 image. For more information on SmartNails, see U.S. patent application Ser. No. 10/044,603, entitled, “Content and Display Device Dependent Creation of Smaller Representations of Images” filed: Jan. 11, 2002, assigned to the corporate assignee of the present invention. SmartNail analysis of JPEG 2000 headers is combined with text-focused OCR analysis to create thumbnails of document images. For more information, see U.S. patent application Ser. No. 10/354,811, entitled, “Reformatting Documents Using Document Analysis Information”, filed Jan. 29, 2003, and U.S. patent application Ser. No. 11/023,142, entitled, “Semantic Document SmartNails,” filed Dec. 22, 2004, both assigned to the corporate assignee of the present invention, and Berkner, Schwartz, & Marle, “SmartNails—display and image dependent thumbnails”, Proceedings of SPIE Vol. 5296, Jan. 21-22, 2004.
Information can be extracted from JPEG 2000 files without doing complete decoding. Both bit allocation and some wavelet coefficient information is available from the packet headers. This information can be used when a page image is compressed solely by JPEG 2000 to do some retrieval or classification operations. For more information, see U.S. patent application Ser. No. 10/044,420, entitled, “Header-based Processing of Images Compressed Using Multi-scale Transforms,” filed Jan. 10, 2002, assigned to the corporate assignee of the present invention.
Web browsers have long been able to prefetch documents based on HTML links or HTTP header lines. In this case, the browser generates additional requests, possibly to different servers based on the content of the current document.
maps.google.com currently provides the ability to view a very large data set, namely, the street maps and aerial photography for much of the world. This data is presented in a web browser and controls are provided to the user to allow pan and zoom. In fact, the user is able to “drag” the current display with the mouse and new regions come into view and are displayed. In the google maps case, the image being shown to the end user is a combination of multiple independently accessible images, which are rendered next to each other. As in the HTML case, the browser is able to generate additional requests for map images near the current displayed region of the map.